"As soon as we discovered that we didn't have not only Coca-Cola but other funding sources on the website, we put it on there," Blair said. "Does that make us totally corrupt in everything we do?"

Funding from the food industry is not uncommon in scientific research. But studies suggest that the funds tend to bias findings. A recent analysis of beverage studies, published in the journal PLOS Medicine, found that those funded by Coca-Cola, PepsiCo, the American Beverage Association and the sugar industry were five times more likely to find no link between sugary drinks and weight gain than studies whose authors reported no financial conflicts.

The group says there is "strong evidence" that the key to preventing weight gain is not reducing food intake - as many public health experts recommend - "but maintaining an active lifestyle and eating more calories." To back up this contention, the group provides links on its website to two research papers, each of which contains this footnote: "The publication of this article was supported by The Coca-Cola Company."

Hill said he had sought money from Coke to start the nonprofit because there was no funding available from his university. The group's website says it is also supported by a few universities and ShareWIK Media Group, a producer of videos about health. Hill said that he had also received a commitment of help from General Mills, as well as promises of support from other businesses, which had not formally confirmed their offers.

He said he believed public health authorities could more easily change the way people eat by working with the food industry instead of against it.

On its website, the group recommends combining greater exercise and food intake because, Hill said, "'Eat less' has never been a message that's been effective. The message should be 'Move more and eat smarter.'"

He emphasized that weight loss involved a combination of complex factors and that his group's goal was not to play down the role of diet or to portray obesity as solely a problem of inadequate exercise.

"If we are out there saying it's all about physical activity and it's not about food, then we deserve criticism," he said. "But I think we haven't done that."

While people can lose weight in several ways, many studies suggest that those who keep it off for good consume fewer calories. Growing evidence also suggests that maintaining weight loss is easier when people limit their intake of high glycemic foods such as sugary drinks and other refined carbohydrates, which sharply raise blood sugar.

Physical activity is important and certainly helps, experts say. But studies show that exercise increases appetite, causing people to consume more calories. Exercise also expends far fewer calories than most people think. A 12-ounce can of Coca-Cola, for example, contains 140 calories and roughly 10 teaspoons of sugar. "It takes 3 miles of walking to offset that one can of Coke," said Barry M. Popkin, a professor of global nutrition at the University of North Carolina at Chapel Hill.

Kelly D. Brownell, dean of the Sanford School of Public Policy at Duke University, said that as a business, Coke "focused on pushing a lot of calories in, but then their philanthropy is focused on the calories out part, the exercise."

In recent years, Coke has donated money to build fitness centers in more than 100 schools across the country. It sponsors a program called "Exercise is Medicine" to encourage doctors to prescribe physical activity to patients. And when Chicago's City Council proposed a soda tax in 2012 to help address the city's obesity problem, Coca-Cola donated $3 million to establish fitness programs in more than 60 of the city's community centers.

The initiative to tax soda ultimately failed.

"Reversing the obesity trend won't happen overnight," Coca-Cola said in an ad for its Chicago exercise initiative. "But for thousands of families in Chicago, it starts now, with the next pushup, a single situp or a jumping jack."